Total mesorectal excision (TME) concept was introduced in the 1980’s, but we must not forget that previously the idea of an extended resection was already crucial for good oncologic results. That is why Goliger used to say that if a male patient was not sexual impotent following a rectal cancer resection, he was not well operated. Both non-involved circumferential resection margin (CRM) and distal resection margin (DRM) are important prognostic factors for oncologic outcomes. In Norway, there is a local recurrence (LR) of 4,1% for stage I-III rectal cancer since 2009, and the 5-year survival is 87%. Laparoscopic mesorectal excision (LaTME) has some technical difficulties. These difficulties are present in recent studies reporting worse oncologic results when using LaTME comparing to open surgery. Additionally, the Australasian Laparoscopic Cancer of Rectum Trial concluded that more long-term observation is necessary to evaluate the role of LaTME in rectal cancer.
Transanal Total Mesorectal Excision (TaTME) was introduced in 2010 with the idea of giving better visualization of resection planes allowing for better oncologic results (LR, CRM and DRM) and a low coloanal anastomosis in patients who might need a stoma. This approach would be good for male patients with lower cancers with a narrow pelvis. However, indications were rapidly extended to higher located cancers. Why should we remove the entire rectum just because? Why should patients loose organ function unnecessarily? Learning curve is not a justification, and patients are not laboratory rats. Concerns arose when publications supporting TaTME were lacking confounders control, were lacking statistical quality analysis, were liked to be biased.
In Norway 157 patients were submitted to TaTME between 2014 and 2018 in seven centers, but three of them suspended it after 5 cases only. An unexpected large number of patients with LR were found, and TaTME was suspended in Norway till an audit results were available. I have addressed these ideas and others in May 2019 in another post (link). Now, the audit results have been published by Wasmuth et al, and this post is aimed at revealing the most important points of it, that justify the suspension of TaTME in Norway. Meanwhile, this technique is still being used in other countries, Portugal included…
Concerns arose because of high local recurrence after TaTME.
The authors collected data following TaTME in seven hospitals (surgeons performed TaTME after a fellowship program in foreign hospitals already performing this procedure) and compared oncologic results with the data from the Norwegian Colorectal Cancer Registry (NCCR), matching with cancer stage (I-III). Anastomotic leak grade C was compared with data from the Norwegian Registry of Gastrointestinal Surgery (NRGS). Mortality rate was also compared with both national registries. Distance to anal verge was between 2 cm and 13 cm, meaning many patients were submitted to unnecessary complete rectal resection losing organ function, possible decreasing Q-o-L, I think. Mean operation time was 274 min. Preoperative QT was given in 21% of TaTME patients, contrasting to 39% of patients in NCCR. T category was lower in TaTME group, and there was no difference in N+ proportion.
In the study period, the estimated local recurrence (LR) rate at 2,4ys:
TaTME group – 11,6%
NCCR group – 2,4% (p<0,001)
Interesting is that all LR occurred in high-volume centers. All recurrences in TaTME group occurred within two years after surgery, six were multifocal and two were extensive. Involved CRM (1mm or less) was found in 12,7% (higher than ROOLAR study – robotic vs laparoscopic). Two-thirds of LR occurred after R0 resection. The meaning of this last data is unclear.
Anastomotic leak in the study period:
TaTME group – 8,4%
NRGS – 4,5% (p=0,047)
The 30-day overall mortality rate in the study period:
TaTME group - 2,5%
NRGS – 0,4% (p=0,008)
Among the 157 patients submitted to TaTME 39 (24,8%) ended with a permanent stoma because of: preoperative decision, intraoperative complications, postoperative complications like anastomotic failure.
Oncologic results of TaTME were worse comparing to national registries.
I believe these results are impressive and justify why two independent letters raising concerns about the high LR rate were responsible for this analysis in Norway. As the authors state, the introduction of a new procedure is not easy, but at least it must have the same oncological outcomes and same functional results as the standard technique. In this study, despite the TaTME cases appeared to have been selected towards more favorable cancers (lower T, smaller tumors) oncological results were worse comparing to national registries, with a 6-fold higher LR rate. Wasmuth et al point out several reasons for a high LR, being gas pressure and surgical manipulation causes of tumour cell leakage into pelvic cavity during surgery also contaminating the distal rectal remnant. This can justify the multifocal and extensive recurrence observed in some cases. According to the authors, the fact that all LR occurred in high-volume centers “suggests that learning curve is of less importance than some might expect”. Suddenly, doing more and more and more does not mean you are doing it better or with better outcomes. The high leak rate means the procedure is difficult and does not support the idea that TaTME allows for a safe anastomosis. Additionally, concern exists because patients are being submitted to an unnecessary low anastomosis. Again, learning curve cannot be a reason, and we must not extend indications just to say, “I am having many cases treated with this technique”. Of concern is also the number of definitive stomas found in this study. Such number lead the authors state that TaTME as a mean to avoid stoma is not supported, eliminating one presumed advantage of this technique.
It is a problem of the method and not a learning curve issue.
From all data presented from this observational study (this is a drawback) it looks like TaTME is not here to stay, at least for now. Eventually, all doctors performing this demanding procedure should stop, analyze their practice and take conclusions. Should we keep doing it or not? Remember that nowadays there is still no consensus about the role of laparoscopy in rectal cancer. Some even say open surgery is better that laparoscopy. Only robotic surgery seems to have advantages mainly in low rectal cancers.
I could not end this post without two sentences which I think are crucial:
“Even very experienced colorectal surgeons who perform TaTME procedures had unsuccessful outcomes. It did not appear to be a learning curve phenomenon so it may be the method (not the training) that is the problem.”
Link to PubMed:
Dr. Carlos Eduardo Costa Almeida
General Surgeon
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